Krunal Patel
Case Study 03 · Stripe Integration

Stripe Integration Designing for Reliable Financial Data

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Connecting a custom Stripe checkout to the company's central CRM so successful payments reliably become accurate financial records.

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DROPPED SYNCHRONIZATIONS
IDEMPOTENT
TRANSACTION PROCESSING
24/7
WEBHOOK AVAILABILITY
The Problem

The client had moved to a custom course platform with direct Stripe checkout. Previously, payments were handled through Ontraport, which automatically recorded the transaction data in the CRM.

The new architecture changed that flow: Stripe successfully processed the payment, but the corresponding transaction record was no longer reaching the CRM.

The result was a dangerous gap between money received and financial data recorded — making revenue reporting and forecasting unreliable.

The requirement was not simply to “sync Stripe with Ontraport.” The integration had to reliably process every webhook, tolerate retries and downstream failures, prevent duplicate records, and preserve enough information to recover from failures.

The Architectural Challenge

Stripe tells you that a payment happened. It doesn't guarantee that every downstream business system successfully recorded it.

The integration therefore had to treat Stripe webhooks as an unreliable delivery boundary: verify every request, safely handle retries, detect duplicates, tolerate CRM failures, and preserve failed payloads for recovery.

Architecture

The integration separates payment notification from CRM persistence.

Stripe remains the source of truth for the payment event. The integration controller verifies the event, resolves the correct CRM contact and product, checks for an existing transaction, and then performs the CRM synchronization. Failures are captured separately so the webhook endpoint can remain healthy.

invoice.paidtransaction lookupREST syncdownstream failureStripeWebhook · invoice.paidIntegration Controller01 · VERIFY SIGNATURE02 · CHECK IDEMPOTENCY03 · RESOLVE + SYNCIdempotency CheckExisting transaction lookupOntraport CRMContact · Product · TransactionFail-Safe LogRaw webhook payloadstripe.logDOWNSTREAM CRM FAILURE DOES NOT DROP THE PAYMENT EVENTPayload preserved in fail-safe log · webhook remains healthy
The Technical Challenge

Why financial webhooks are hard

Security

Cryptographic Verification

Every incoming webhook is verified using Stripe's official signature verification mechanism before any business logic runs. Invalid or spoofed requests are rejected immediately.

The result

Prevente untrusted payloads from entering the synchronization pipeline.

Duplication

Idempotent Processing

Stripe can retry webhook delivery when the original request is not acknowledged successfully. The integration therefore checks the external transaction/order identifier before creating the CRM record.

The result

The same payment can be delivered multiple times, but it can only be recorded once in the CRM.

Mapping

Dynamic Data Mapping

Stripe payloads contain the identifiers needed to reconstruct the corresponding CRM records. The integration resolves the customer, locates or creates the required CRM contact, maps Stripe product IDs to CRM products, and creates missing products when necessary.

The result

No manual product creation or contact management is ever required.The synchronization can therefore handle new and existing customers and products without relying on a completely pre-populated CRM.

Resilience

Fail-Safe Error Handling

A downstream CRM failure should not turn into a dead Stripe webhook endpoint. Instead of repeatedly failing the webhook while Ontraport is unavailable, the integration captures the raw payload in a fail-safe log and acknowledges the webhook.

The result

The payment event remains available for recovery, while temporary CRM failures cannot take the Stripe endpoint offline.

MY ROLE

I designed and implemented the integration end to end — from Stripe webhook verification and idempotent processing to CRM contact and product mapping, transaction synchronization, and fail-safe error handling. I also designed the recovery path for downstream failures so payment events could be preserved without taking the webhook endpoint offline.

PRODUCTION STACK

Backend & DB

PHPMySQL

Infra & Services

Stripe API/SDKWebhooksOntraport REST APIResend
Results

Impact & Stability

Zero Dropped Synchronizations

Every Stripe payment reaching the integration was either synchronized successfully with the CRM or captured in the fail-safe path for recovery.

Financial Forecasting Restored

Direct Stripe payments once again flowed into the CRM as transaction records, restoring the financial data required for accurate reporting and forecasting.

Resilient Webhook Operations

The webhook endpoint remained consistently healthy without requiring manual intervention, even when downstream CRM processing encountered failures.

Building an Integration You Can't Afford to Get Wrong?

Let's design the failure handling before production does it for you.

Payments, webhooks, CRM synchronization, AI workflows, and other systems where a failed request can become a business problem.

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